As general methods for producing an ester derivative, there have been known a method comprising chlorinating a carboxylic acid derivative by using a halogenating agent and reacting the resultant product with an alcohol derivative in an organic solvent in the presence of abase, a method comprising reacting a carboxylic acid derivative with an alcohol derivative in an organic solvent by using a condensing agent, and similar methods.
As a method for producing a 2-aminonicotinic acid ester derivative, Patent Literature 1 discloses a method for producing a 2-aminonicotinic acid ester derivative represented by the following reaction formula:

wherein M is an alkali metal and X is a halogen atom.
Although the aforementioned method of Patent Literature 1 can produce a 2-aminonicotinic acid ester derivative in a high yield at a high purity, the viscosity of the reaction solution tends to be high and it is difficult to achieve a volume efficiency of 10% or more in production. Moreover, since a water-soluble polar solvent is used, it is impossible to eliminate concerns about environmental load in solvent recycle and waste liquid treatment after the reaction.